The success of the International Space Station (ISS) is dependent upon Extra Vehicular Robotics (EVR) for assembly and maintenance. The ISS EVR System encompasses two major types of robotic systems: Single-Manipulator operations and Dexterous Manipulator operations. The three single-manipulator robots on the ISS include the Canadian Space Station Remote Manipulator System(SSRMS), the Japanese Experimental Module Robotic Manipulator System (JEM RMS) and the Russian European Robotic Assembly (ERA) and provide for assembly, maintenance, viewing and Extravehicular crew support. The Canadian Space Agency built Special Purpose Dexterous Manipulator (SPDM) is primarily used for maintenance activities requiring great accuracy. The robotic systems are crucial for the ISS in the roles of assembly; translation of payloads and crew to worksites; providing power; data and video to "dead" payloads; providing viewing to remote areas; providing assistance to extravehicular activities; and providing maintenance. The primary uses of the EVR systems and the uses of the hardware are described. Other hardware items crucial to EVR but not part of the EVR system are also discussed.